Just as the unique curved guide tube concepts represent an improvement over past systems, particularly ones using a “center-of-rotation” of the instrument at the incision, the concepts set forth herein represent still other improvements by further minimizing the rotation or pivoting at the incision. In some embodiments described herein only rotation occurs at the incision and no pivoting. Such pivoting causes stress at the incision and can damage tissue. In other embodiments described herein neither pivoting, rotation nor translation occur at the incision.